Adafruit

This rotary encoder is a high quality 24-pulse encoder, with detents and a nice feel. This encoder also has a push-button built into it so you can press onto the knob to close a separate switch. One side has a 3 pin connector (ground and two coding pins) and the other side has two pins for a normally-open switch.

The matrices use a driver chip that does all the heavy lifting for you: They have a built in clock so they multiplex the display. They use constant-current drivers for ultra-bright, consistent color, 1/16 step display dimming, all via a simple I2C interface.

These LED panels take care of all the work of making a big matrix display. Each panel has six 8x8 red matrix modules, for a 16x24 matrix. The panel has a HT1632C chip on the back with does all the multiplexing work for you and has a 3-pin SPI-like serial interface to talk to it and set LEDs on or off (you cannot set the LED to be individually dimmed, as in 'grayscale'). There's a few extras as well, such as being able to change the brightness of the entire display, or blink the entire display at 1 Hz.